London - One of the most common sexual problems in men could be tackled by a battery-powered skin patch.
The adhesive patch, about a square inch in size, is designed to reduce the activity of the pelvic muscles in men affected by premature ejaculation.
Research shows that the patch, worn on the perineum — the area between the anus and the scrotum — leads to a near fourfold increase in ejaculation time, and a new trial is starting this month.
Ejaculation is classed as premature when it occurs within one minute. Typically, intercourse lasts far longer: one study, published in the Journal of Sexual Medicine in 2005, involving 500 couples, found that the average time was about five-and-a-half minutes.
The exact cause of premature ejaculation is not known, and there are likely to be many factors, including depression, stress and relationship problems.
The brain chemical serotonin may also play a role — low levels speed up ejaculation time. Antidepressant drugs that make more serotonin available, called selective serotonin reuptake inhibitors (SSRIs), such as sertraline and fluoxetine, are widely used as a treatment.
But they don’t work for everyone and can cause side-effects such as anxiety and gastric issues.
Anaesthetic creams and sprays such as lidocaine can help by making the penis less sensitive.
The new single-use patch acts on the muscles at the base of the penis - mainly the bulbospongiosus - that contract, forcing semen out, during ejaculation.
The patch is used for about ten minutes before intercourse and transmits mild electrical impulses to the muscles.
The theory is that this neuromuscular transcutaneous electrical stimulation keeps the muscles contracted for several minutes. They are therefore temporarily unable to provide the rhythmic contractions needed for ejaculation.
The strength of the stimulation can be controlled by an app.
Research published in the International Journal of Impotence Research last year, involving 20 men who were given a commercially available electrical stimulation device to use, showed stimulating these muscles does help.
Ejaculation time increased by 3.5 times, according to the study at the Technion Israel Institute of Technology in Haifa.
Now a trial is under way at Stanford University, in America. Men will use the patch before sexual activity for four months.
"No treatment for premature ejaculation has been found to be ideal," says Professor Raj Persad, a consultant urologist at Bristol Urology Associates.
"The approach draws on the potential for using the pelvic floor muscles. Results are encouraging and, if proven of clinical value, may be a cost-effective way of treating this distressing problem for men."